The processes of sexual differentiation in the populations can be modified by different environmental influences. Low protein or caloric supply in the first 24 months of life can produce substantial modifications in the ontogenetic evolution, and can produce adaptive responses to allow growth. The aim of this study was to analyze the growth and sexual differentiation patterns in a sample of 215 children from 1 to 24 months old, from the outskirts of La Plata City and with a low-income living. Different cephalic and body measurements were taken. Statistical analysis was performed by 1) the Kolmogorov-Smirnov test; 2) mean, standard deviation, z scores and; 3) ANOVA and, in case of significant differences, LSD test. Z score was between -1 and -2.35 for W/A and H/A, between -0.59 and -1.66 for head circumference and between -0.1 and -1.22 for W/H with respect to the standard. Body weight was dimorphic only for 24-month-old children, head circumference for 8, 16 and 21-month-old children. Weight and weight/height relationship did not present dimorphism. These results allow to correlate undernutrition with changes in the manifestations of sexual differentiation in early growth stages.